Capacitive buttons have many advantages and have gradually replaced the conventional mechanic buttons. Capacitive buttons are now widely used in various computer systems such as PC, notebook computer or all-in-one PC (AIO PC).
When an object (such as a user's finger) touches the capacitive button, the capacitance of the capacitive button is changed and an internal controller of the computer system detects this to perform various system control functions. Furthermore, tens of conventional mechanic buttons may be replaced by capacitive buttons.
Currently, the power button still mainly uses the conventional mechanic button. For the power button to be implemented by the capacitive button, a suitable processing flow is required to perform functions such as powering on, power off, shutting down, and sleep state.